Preparations for the next phase of RF conditioning continues in the first part of the Accelerator – the Normal Conducting Linac. Radio frequency power will be sent through the waveguides and stubs from the equipment installed in the adjacent Klystron Gallery building, for plasma conditioning in the ion source and re-conditioning of the RFQ cavities to start. The next stage will then be to proceed to the MEBT section, where bunchers will be included, as well as the Drift Tube Linac tank no 1.
Cryogenic Distribution System
Welding works are in progress in the Spokes section. All 13 header units connecting the valve boxes to the cryogenic distribution system have been positioned and internal piping aligned. Tack welding is ongoing.
The cryogenic system for the elliptical cavities in the medium and high beta sections will be subject to cleaning and flushing over the coming period.
The Cryogenic Distribution System supplies cold helium from the large coldbox in the Klystron Gallery’s coldbox hall via a culvert to the linac, to the high beta, medium beta and spoke sections. Cold helium will flow all the way down to the spoke section’s end box, where it will be circulated back to the Cryo Compressor building via a helium collector pipe, to be cleaned and used over and over again. Valve boxes provide the interface to the cryomodules via a jumper connection.
Completing the Cryogenic Distribution System is a prerequisite to start the installation of cryomodules in the linac.
Serial testing of cryomodules is ongoing both at the ESS on-site test stand (elliptical) and at the Freia lab in Uppsala (spokes).
The upper and lower parts of the Monolith vacuum vessel have been sealed with a weld. A connection pipe between the proton beam window port block and the vessel was also welded in place. These works are carried out under the Spanish ESS Bilbao in-kind agreement.
Once welding is completed, the vessel will be cleaned on the inside, preparing for the next steps, including installation of inner shielding blocks. Inner shielding positioning blocks have already been welded to the Monolith vessel bottom.
Pipe connecting the Linac to the Target
The 12.3-metre-long pipe connecting the linac and the target via the proton beam drift room is being prepared for installation. The pipe will be placed in a narrow space called the proton beam drift room, connecting it to the remote clamp in the Monolith area. A concrete plug will then be put in place on the tunnel-side.
The first lower shielding blocks for the beamlines for instruments ODIN and DREAM have been positioned close to the south sector bunker in Experimental Hall 1.
The two floors of the DREAM cave are in place, and painting of the concrete facades has started. Precast blocks for the labyrinth entrance to the cave have also been lifted in place.